What I learned today about the hot air balloon is that if you have a lot of people in the basket then you have to use more gas.Also if its hot outside then you have to use more fire.The hot air balloon was invented in the seventeen hundreds.The hot air balloon has no door but there are stairs.To make the hot air balloon fly you have to pull down a lever that makes the fire go high in the air so that the balloon doesn’t fall on the ground.The air that goes out of the hole is hot air.